Sfi System Vc Output Circuit

Engine. Lexus Is250, Is220D. Gse20 Ale20
4Gr-Fse Engine Control System. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK MIL

CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM

CHECK THROTTLE BODY ASSEMBLY (CHECK MIL ILLUMINATED)

CHECK ACCELERATOR PEDAL ASSEMBLY (CHECK MIL ILLUMINATED)

CHECK VVT SENSOR FOR INTAKE CAMSHAFT BANK 1 (CHECK MIL ILLUMINATED)

CHECK VVT SENSOR FOR EXHAUST CAMSHAFT BANK 1 (CHECK MIL ILLUMINATED)

CHECK VVT SENSOR FOR INTAKE CAMSHAFT BANK 2 (CHECK MIL ILLUMINATED)

CHECK VVT SENSOR FOR EXHAUST CAMSHAFT BANK 2 (CHECK MIL ILLUMINATED)

CHECK FUEL PRESSURE SENSOR (CHECK MIL ILLUMINATED)

CHECK BATTERY CURRENT SENSOR ASSEMBLY (CHECK MIL ILLUMINATED)

CHECK HARNESS AND CONNECTOR

SFI SYSTEM - VC Output Circuit


DESCRIPTION

The ECM constantly generates 5 V power from the battery voltages supplied to the +B (BATT) terminal to operate the microprocessor. THe ECM also provides this power to the sensors through the VC output circuit.
When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied power through the VC circuit are inactivated because the power is not supplied from the VC circuit. Under this condition, the system does not start up and the MIL does not illuminate even if the system malfunctions.
HINT:
Under normal conditions, the MIL is illuminated for several seconds when the ignition switch is first turned to ON. The MIL goes off when the engine is started.

WIRING DIAGRAM

Refer to ECM Power Source Circuit (Click here).

INSPECTION PROCEDURE

1.CHECK MIL
  1. Check that Malfunction Indicator Lamp (MIL) lights up when turning the engine switch on (IG).

    OK:
    MIL lights up.


OK
SYSTEM IS OK
NG


2.CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM
  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and tester ON.

  1. Check the communication between the tester and ECM.

    Result:

    Result
    Proceed to
    Communication is possible
    A
    Communication is not possible
    B


A
GO TO MIL CIRCUIT
B


3.CHECK THROTTLE BODY ASSEMBLY (CHECK MIL ILLUMINATED)
  1. Disconnect the throttle body connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    Proceed to
    MIL illuminates
    A
    MIL does not illuminate
    B
  1. Reconnect the throttle body connector.



A
REPLACE THROTTLE BODY ASSEMBLY
B


4.CHECK ACCELERATOR PEDAL ASSEMBLY (CHECK MIL ILLUMINATED)
  1. Disconnect the accelerator pedal position sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    Proceed to
    MIL illuminates
    A
    MIL does not illuminate
    B
  1. Reconnect the accelerator pedal position sensor connector.



A
REPLACE ACCELERATOR PEDAL ASSEMBLY
B


5.CHECK VVT SENSOR FOR INTAKE CAMSHAFT BANK 1 (CHECK MIL ILLUMINATED)
  1. Disconnect the VVT sensor for intake camshaft bank 1 connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    Proceed to
    MIL illuminates
    A
    MIL does not illuminate
    B
  1. Reconnect the VVT sensor for intake camshaft bank 1 connector.



A
REPLACE VVT SENSOR FOR INTAKE CAMSHAFT BANK 1
B


6.CHECK VVT SENSOR FOR EXHAUST CAMSHAFT BANK 1 (CHECK MIL ILLUMINATED)
  1. Disconnect the VVT sensor for exhaust camshaft bank 1 connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    Proceed to
    MIL illuminates
    A
    MIL does not illuminate
    B
  1. Reconnect the VVT sensor for exhaust camshaft bank 1 connector.



A
REPLACE VVT SENSOR FOR EXHAUST CAMSHAFT BANK 1
B


7.CHECK VVT SENSOR FOR INTAKE CAMSHAFT BANK 2 (CHECK MIL ILLUMINATED)
  1. Disconnect the VVT sensor for intake camshaft bank 2 connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    Proceed to
    MIL illuminates
    A
    MIL does not illuminate
    B
  1. Reconnect the VVT sensor for intake camshaft bank 2 connector.



A
REPLACE VVT SENSOR FOR INTAKE CAMSHAFT BANK 2
B


8.CHECK VVT SENSOR FOR EXHAUST CAMSHAFT BANK 2 (CHECK MIL ILLUMINATED)
  1. Disconnect the VVT sensor for exhaust camshaft bank 2 connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    Proceed to
    MIL illuminates
    A
    MIL does not illuminate
    B
  1. Reconnect the VVT sensor for exhaust camshaft bank 2 connector.



A
REPLACE VVT SENSOR FOR EXHAUST CAMSHAFT BANK 2
B


9.CHECK FUEL PRESSURE SENSOR (CHECK MIL ILLUMINATED)
  1. Disconnect the fuel pressure sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    Proceed to
    MIL illuminates
    A
    MIL does not illuminate
    B
  1. Reconnect the fuel pressure sensor connector.



A
REPLACE FUEL PRESSURE SENSOR
B


10.CHECK BATTERY CURRENT SENSOR ASSEMBLY (CHECK MIL ILLUMINATED)
  1. Disconnect the battery current sensor connector.

  1. Turn the engine switch on (IG).

  1. Check the MIL.

    Result:

    Result
    Proceed to
    MIL illuminates
    A
    MIL does not illuminate
    B
  1. Reconnect the battery current sensor connector.



A
REPLACE BATTERY CURRENT SENSOR ASSEMBLY
B


11.CHECK HARNESS AND CONNECTOR


    Lexus Is250, Is220D. Gse20 Ale20.4Gr-Fse Engine Control System.Sfi System.Sfi System  Vc Output Circuit
  1. Disconnect the throttle body connector.

  1. Disconnect the accelerator pedal position sensor connector.

  1. Disconnect the VVT sensor for intake camshaft bank 1 connector.

  1. Disconnect the VVT sensor for exhaust camshaft bank 1 connector.

  1. Disconnect the VVT sensor for intake camshaft bank 2 connector.

  1. Disconnect the VVT sensor for exhaust camshaft bank 2 connector.

  1. Disconnect the fuel pressure sensor connector.

  1. Disconnect the battery current sensor connector.

  1. Disconnect the D3, D5 and A5 ECM connectors.

  1. Check the resistance.

    Standard resistance (Check for short):
    Tester Connections
    Specified Conditions
    VC (E3-29) - Body ground
    10 kΩ or higher
    VC2 (E5-29) - Body ground
    10 kΩ or higher
    VCPA (A6-35) - Body ground
    10 kΩ or higher
    VCP2 (A6-27) - Body ground
    10 kΩ or higher
  1. Reconnect the ECM connectors.

  1. Reconnect the canister pump module connector.

  1. Reconnect the fuel pressure sensor connector.

  1. Reconnect the VVT sensor for exhaust camshaft bank 2 connector.

  1. Reconnect the VVT sensor for intake camshaft bank 2 connector.

  1. Reconnect the VVT sensor for exhaust camshaft bank 1 connector.

  1. Reconnect the VVT sensor for intake camshaft bank 1 connector.

  1. Reconnect the accelerator pedal position sensor connector.

  1. Reconnect the throttle body connector.

  1. Reconnect the battery current sensor connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM